Conveyor system for drive-in restaurants

ABSTRACT

A conveyor system for drive-in restaurants consisting of a plurality of tray-supporting carriages which are electrically driven to move along a track system including rails from which they derive their power, said track system including a holding loop, a delivery loop branching from and returning to said holding loop, a series of station loops branching from and returning to said delivery loop, a switch operable to divert carriages from the holding loop to the delivery loop, said switch being operable to divert only a pre-selected carriage, a series of switches each operable to divert carriages from said delivery loop to one of said station loops, each of said latter switches being pre-set to divert only one of said carriages, and means operable to arrest the movement of each carriage in its individual station loop and at other selected points of the track system.

United States Patent Kropf [451 July4, 1972 [54] CONVEYOR SYSTEM FOR DRIVE-IN RESTAURANTS Frederic F. Kropf, 2419 N. 72nd Place, Kansas City, Kans. 66109 [22] Filed: Aug. 17, 1970 [21] Appl.No.: 64,378

[72] Inventor:

l 5 6] References Cited UNITED STATES PATENTS 2,614,506 l0/l952 Mullerheim ..l04/88 3,174,438 3/1965 Hariton 2,096,894 10/1937 Hall ..246/1l5 Primary Examiner-Arthur L. La Point Assistant ExaminerGeorge H. Libman Att0rney.lohn A. Hamilton [57] ABSTRACT A conveyor system for drive-in restaurants consisting of a plurality of tray-supporting carriages which are electrically driven to move along a track system including rails from which they derive their power, said track system including a holding loop, a delivery loop branching from and returning to said holding loop, a series of station loops branching from and returning to said delivery loop, a switch operable to divert carriages from the holding loop to the delivery loop, said switch being operable to divert only a pre-selected carriage, a series of switches each operable to divert carriages from said delivery loop to one of said station loops, each of said latter switches being pre-set to divert only one of said carriages, and means operable to arrest the movement of each carriage in its individual station loop and at other selected points of the track system.

3 Claims, 11 Drawing Figures P'A'TE'NTEDJuL 4 1912 3.673.967

sum 3 or 4 INVENTOR.

fiederic F Kmp/ WAW Afro/way.

CONVEYOR SYSTEM FOR DRIVE-IN RESTAURANTS This invention relates to new and useful improvement in conveyor systems, and has as its object the provision of a conveyor system especially adapted for use in drive-in restaurants, whereby food ordered by passengers in automobiles parked at designated stations, said ordering already being widely performed by intercom systems, is also delivered automatically to the proper stations from the restaurant building on trays moved by the conveyor. The trays are of course returned by the conveyor to the restaurant building when the food has been consumed, and the trays may also be used collecting the money in payment for the food. Thus any requirement for live waitresses or waiters, commonly known as carhops, is virtually eliminated, permitting a great saving in salaries.

Other objects are simplicity and economy of construction, and efficiency and dependability of operation.

With these objects in view, as well as other objects which will appear in the course of the specification, reference will be had to the accompanying drawing, wherein:

FIG. 1 is a schematic top plan view of the track and related parts of a conveyor system embodying the present invention, not to scale, including a partial wiring diagram,

FIG. 2 is an enlarged, fragmentary sectional view taken on lihe Il-II of FIG. 1, showing details of construction, and showing one of the carriages at the moment it actuates the switch to divert it from the delivery loop of the track to its individual station loop of the track,

FIG. 3 is a sectional view taken on line III-1H of FIG. 2, showing the switch activated in solid lines and deactivated in dotted lines,

FIG. 4 is a sectional view taken on line IV IV of FIG. 3,

FIG. 5 is a schematic wiring diagram of the switch,

FIG. 6 is a schematic wiring diagram of the switch for diverting carriages from the holding loop to the delivery loop of the track,

FIG. 7 is a fragmentary view similar to FIG. 2, but taken on line VII-VII of FIG. 1, showing a carriage at the moment it actuates a safety device to prevent collision of carriages at points of convergence of the track loops,

FIG. 8 is a sectional view taken on line VIII-VIII of FIG. 7,

FIG. 9 is an enlarged view similar to FIG. 1, showing a point of convergence of the track loops, and including a schematic wiring diagram of the collision-prevention device,

FIG. 10 is a reduced, fragmentary side elevational view of a section of the conveyor, showing the tray supported by one of the carriages, and

FIG. 11 is an enlarged, fragmentary sectional view taken on line XlXI of FIG. 10.

Like reference characters refer to similar parts throughout the several views, and referring first to FIG. 1, it will be seen that the track on which the carriages move is designated generally by the numeral 2, and consists of left and right rails 4 and 6 of electrical conducting material which are set flush into the upper surface of a platform 8 of insulating material such as wood, as best shown in FIG. 4, respectively adjacent the opposite sides of a continuous slot 10 formed along the midline of said platform, the platform being wider than the track itself. Since slot 10 must be continuous as will appear, the portions of the platform must be positioned relative to each other by means not obstructing said slot, for example by securing the outer edges of said platform to the opposite vertical walls of a rectangular tubular housing 12 by means of screws 14 (see FIG. 4), said housing extending above the platform to form a tunnel 16 through which the carriages move, and below said platform to form a chamber 18 for carrying the switches, as will appear. A slot 20 is formed in the bottom of the housing to be coextensive with slot 10 of platform 8. Housing 12 may be affixed to a ground standard (not shown) by brackets 22 (see FIG. 4) whereby to support said housing at a suitable distance above an automobile parking surface.

Track 2 carries a series of wheeled carriages each designated generally by the numeral 24. Details of structure of one of the carriages is shown in FIGS. 2, 3, and 4. It includes an electric motor 26 having a clamp ring 28 affixed thereabout on which are mounted a pair of laterally spaced apart caste red wheels 30 which ride on the top surface of platform 8 at opposite sides of slot 10, and which are the rear wheels of the carriage. Affixed to the motor and extending forwardly therefrom is a bracket 32 to the forward end of which is affixed a gear reduction unit 34, the drive shaft 36 of motor 26 being operatively connected by coupling 38 to the input shaft 40 of reducer 34 (see FIG. 2). Reducer 34 turns a pair of laterally projecting horizontal axles 42, to the outer end of each of which is aflixed a wheel 44 engaging platform 8. Wheels 44 are thus the drive wheels, and are the front wheels of the carriage, moving the carriage forwardly whenever motor 26 is in operation. The peripheral surfaces of all of wheels 30 and 44 are formed of insulating material, whereby to prevent the possibility that they might cause a short-circuit connection between rails 4 and 6 of the track.

Affixed to the upper and lower surfaces of reducer 34 are an upper plate 46 and a lower plate 48 of insulating material, said plates being horizontal and extending forwardly and rearwardly from said reducer. A pair of laterally spaced apart posts 50 are carried for vertical sliding movement by the forward portions of said plates, and a similar pair of posts 50 by the rearward portions for collecting said plates. As best shown in FIG. 2, each post 50 is vertically slidable in holes 52 formed therefor in plates 46 and 48, and are formed of conducting material. At its lower end, each post carries a contact wheel 54 of conducting material for rotation on a horizontal transverse axis, and a contact brush 55 urged against said wheel by a spring 56. The two left wheels 54 engage left rail 4, and the two right wheels 54 engage right rail 6. Left posts 50 are urged downwardly, whereby to insure good contact of the associated wheels 54, by a strip 56 of spring conducting material secured at its mid-point to the top surface of plate 46 by screw 58, and secured at its respective ends, as by screws 60 (see FIG. 3) to the upper ends of the two left posts 50. Similarly, a spring contact strip 62 is connected to plate 46 by screw 64, and to the upper ends of right posts 50 by screws 66. Posts 50 extend above plate 46, so that the spring action of strips 56 and 62 urges said posts downwardly to press contact wheels 54 firmly against the rails. The lead wires 68 and 70 of motor 26 are connected respectively to strips 56 and 62. Thus when even one of left wheels 54 engage rail 4, and one of right wheels 54 engages rail 6, motor 26 is operative and the carriage moves forwardly.

Rigidly affixed in the forwardly projecting end portions of plates 46 and 48 as by nuts 72, is the upper end portion of a support rod 74. Said rod extends downwardly through slot 10 of platform 8 and slot 20 of housing 12, depending below said housing and terminating in an eye 76 in which is pivotally engaged the eye 78 of a rod frame 80 (see FIGS. 10 and 11) the details of which are not important, but which is capable of supporting a tray 82 for carrying food, beverages, and the like. Trays 82 should be disposed at an elevation above the ground convenient to the windows of an automobile. The inclusion of rod 74 in slot 10 of platform 8 guides the carriage accurately along the track as front wheels 44 are driven, castered rearward wheels 30 permitting the rearward end of the carriage to trail arcurately. Directly within slot 10, rod 74 is provided with a sleeve 84 of insulating material, so that the rod cannot cause short circuiting between rails 4 and 6.

Extending transversely above plate 46, and connected thereto by bracket 86, is a horizontal bar 88 in which a series of transversely spaced apart holes 90 are formed, into each of which an upwardly projecting switch operating button 92 may be inserted. Buttons 92 are inserted only in certain of said holes, in a different pattern on each carriage, as will appear. Buttons 92 constitute the highest points of the carriage.

Referring again to FIG. 1, it will be seen that track 2 constitutes a holding loop X, which is closed and continuous, a delivery loop Y which leaves loop X at point 94 and returns thereto at point 96, and a series of any desired number of station loops A, B, C, D, E, and F each leaving loop Y at point 98 and returning thereto at point 100. Alternatively, track Y and the major portion of track X may be viewed as a single continuous delivery loop, with the track portion between points 94 and 96 being viewed as a short circuit" between portions of the single delivery loop, whereby to form loop X. The carriages always move in the same direction in each loop, as indicated by the directional arrows. Thus there are points of tract divergence at point 94 and each point 98, and points of convergence at point 96 and each point 100. Loops A, B, C, D, E, and F, each of which receives only one of the carriages, which are correspondingly designated A, B, C, D, E, and F, anda major portion of loop Y, are disposed above the parking area of a drive-in restaurant, so that each station loop is disposed conveniently to the parking space of a single automobile, while holding loop X and the remainder of loop Y are preferably disposed within the restaurant building.

Rails 4 and 6 are continuous around all of the track loops, except that at each convergence and divergence of the loops, at the point where rails 4 and 6 would otherwise intersect, said rails are cut away, as indicated at 102 in FIGS. 1 and 9, so that said rails do not contact and do not lie in each others paths. This prevents the short-circuiting which would otherwise occur when the two left contact wheels 54 of a carriage (or the two right contact wheels) simultaneously engaged both of the rails. However, the spacing between the front and rear contact wheels of the carriages must be sufficient to bridge the gap created by cutaways 102, so that at least one left and one right contact wheel will always be in engagement with its proper rail. Also, each station loop A, B, C, D, E, and F, or at least one rail thereof, is provided with a stop" section 104 which is electrically insulated from the adjoining sections of said rail. As shown, said stop sections constitute sections of right rail 6, which may for convenience be designated the hot rail, while left rail 4 may be designated the ground rail. Each stop section 104 is of greater length than the spacing between the front and rear contact wheels 54 of a carriage, so that a carriage moving thereonto will halt for lack of electric power, but is spaced apart from the adjacent sections of rail 6 by distances less than said wheel spacing. Similarly, rail 6 of track 2 is provided with a stop section 106 in both tracks approaching each convergence point 96 and 100, just before said point of convergence, and one or more stop sections 108 in delivery loop Y between the point loop Y leaves loop X and the first station loop (loop E as shown).

As shown in FIG. 1, the system is furnished with electric power by a pair of live wires 1 and l 12 connected to a stepdown transformer 114 which reduces the voltage to a level suitable for motors 26, say 24 volts. One terminal of said transformer is connected by wire 1 16 to all portions of hot rail 6 except stop sections 104, 106, and 108 thereof, and its opposite terminal is connected by wire 118 to all sections of ground rail 4.

Each stop section 104 of rail 6 is connected to an adjacent, continuously charged section of said rail by a wire 120 in which is connected a normally open pushbutton switch 122, said switches being conveniently mounted on the intercom stand serving that particular station. Thus a carriage stops automatically whenever it enters on any stop section 104, which is the serving position for an automobile at that station, but may be again started by pressing the associated pushbutton 122 momentarily until the right front contact wheel 54 of the carriage again engages a continuously charged section of rail 6. Similarly, stop section 108 is connected by a wire 124 to an adjacent section of rail 6, and a pushbutton switch 126 is connected in said wire. This is a station for loading and unloading of the trays 82 by the restaurant personnel, and is preferably disposed within the restaurant building.

To mechanically switch (or divert to avoid confusion with references to electrical switches), there is provided a mechanical switch 128, as best shown in FIGS. 2, 3, and 4. Said switch includes a curved diverter bar 130 pivoted to the lower surface of plafiorm 8, within chamber 18, on a vertical axis, by means of screw 132. Said bar is movable by a rod 134 pivoted to the outer surface thereof, as at 136, and extending horizontally therefrom, said rod being afiixed at its opposite end to the movable armature 138 of a solenoid coil 140 pivoted to platform 8 at 142. When said coil is not energized, a spring 144 within coil 140 moves bar to the dotted line position of FIG. 3, wherein it does not obstruct slot 10 and allows support rod 74 of an approaching carriage to move into the straight-through extent of said slot, so that the carriage is not diverted to the divergent track loop. This is the open" position of the switch When coil is energized, it moves bar 130 to the solid line position of FIG. 3, wherein it obstructs the straight-through extent of slot 10 and thus diverts support rod 74 into slot 10 of the divergent track loop. This is the closed" position of the switch.

Solenoid coil 140 is energized by an electric circuit diagranuned in FIG. 5, said circuit extending from hot rail 6 through wire 146, a plurality (three shown) of electric switches 148, 150, and 152 connected in series, wire 1S4, coil 140 and wire 156 to ground rail 4. Thus coil 1 0 is energized whenever all of switches 148, 150, and 152 are closed. Each of said switches, which may be microswitches, is provided with an operating button 158 which is depressible by a lever 160 pivoted to said switch. Said switches are aflixed to a bridge member 162 affixed to platform 8 and rising thereabove, through which the carriages pass just as they approach the switch point. Said switches are mounted on the top arm of said bridge member, so that as a carriage passes therebeneath, the switch operating buttons 92 of the carriage engage and pivot the operating levers 160 of the switches to activate the corresponding switch, if there is a button 92 aligned with each switch, or will leave any switch unactuated if there is no corresponding button 92 on the carriage.

Switches 148, 150, and 152 may each be either normally open or normally closed, and there must be a different combination for each switch 128, in order that only the carriage destined for each station loop will be diverted to that loop (carriage A to loop A, etc.). With three switches as shown, there are eight possible different combinations, as follows:

Hence, in FIG. 5, which diagrams the circuit for switch 128 of station loop E, switches 148 and 152 are nonnally open, and switch is normally closed. Carriage E is likewise provided with buttons 92 corresponding in lateral spacing to levers of switches 148 and 152, but not with switch 150. Thus whenever carriage E passes beneath this particular combination of switches, buttons 92 of the carriage will close switches 148 and 152, while switch 150 will simply remain closed, and the circuit of solenoid coil 140 will be completed, moving switch bar 130 to divert carriage E into station loop E. Operating levers 160 extend sufficiently far, in the direction of carriage travel, to keep the coil energized until support rod 74 of the carriage has passed the switch bar 130. As soon as buttons 92 have been moved out of engagement with levers 160, switches 148 and 152 immediately open so that no following carriage will also be diverted. No carriage having any other combination of buttons will actuate this particular switch, since every other carriage will have at least one button where carriage E does not, in which case switch 150 would be opened, or will not have a button where carriage E does, in which case either or both of switches 148 and 152 will remain open. Each of the switches 128 to the other station loops has its own individual combination, so that each carriage directed into delivery loop Y will automatically find its way to its corresponding station loop, and no other.

With regard to the possibility listed for Carriage H in the table, in which all of the switches 148, 150, and 152 are normally closed, this would require a carriage l-I having no buttons 92, and the corresponding solenoid coil would remain energized at all times except when an incorrect carriage opens one of the switches. Since the virtually constant energization of a solenoid is not desirable, it is considered desirable to discard this possible combination, and hence to use only combinations including at least one normally open switch, so that no solenoid is ever actuated except momentarily when actually needed. This leaves seven usable combinations, although only six are used in the embodiment shown. Also, if more than three switches are used, the number of possible combinations is doubled for each switch added. In this connection, it will be noted that each bridge member 162 is adapted to receive and carry as many as five switches, although only three are illustrated, and that each carriage bar 88 is bored to receive as high as five corresponding operating buttons 92 where required. In this manner, the system may readily be adapted to serve almost any number of stations.

At point 94 of the track, where delivery loop Y diverges from holding loop X, there is provided a diverter switch 164 (see FIG. 1) which is mechanically identical to switches 128, but requires a more involved electrical system, as diagrammed in FIG. 6. Switch 164 is actuated by a solenoid coil 166, the same as switches 128, and said coil is controlled by an electrical system including three switches 168, 170, and 172 mounted on a bridge member 174 over the track just before point 94 thereof. Said switches are similar to switches 148, 150, and 152, each having a control button 176 (and lever 160) operated by buttons 92 of the various carriages. However, switches 168, 170, and 172, instead of being singlethrow, normally open or closed switches as are switches 148, 150, and 152, are each of the double throw type, each having a nonnally closed contact 178 and a normally open contact 180 which is closed by the action of pushbutton 176. The control system also includes a series of single-pole, double throw switches 182, 184, and 186 corresponding respectively to switches 168, 170, and 172, and which may be mounted in a control box remote from the track. Switches 182, 184, and 186 each have a normally closed contact 188, and a normally open contact 190. The normally closed contact 188 of each of switches 182, 184, and 186 is connected by a wire 192 to the normally closed contact 178 of its corresponding switch 168, 170, or 172, and the normally open contacts 190 of switches 182, 184, and 186 are each connected by a wire 194 to the normally open contact 180 of its associated switch 168, 170, and 172. The common contact of switch 182 is connected to the common contact of switch 170 by wire 196, and the common contact of switch 184 is connected to the common contact of switch 172 by wire 198. The common contact of switch 168 is connected through wire 200, a normally open switch 202 mounted in the control box containing switches 182, 184, and 186, and wire 204 to hot rail 6. The common contact of Switch 186 is connected through wires 206 and 208, solenoid coil 166 and wires 210 and 212 to ground rail 4.

Switches 182, 184, and 186 are operated, to close them on their normally open contacts by operating fingers 214 mounted on plungers 216 carried by the control box 218 which carries said switches, each plunger being depressible against a spring 220 by manual force, their upper ends being exposed exteriorly of box 218 and constituting pushbuttons A, B, C, D, E, and F respectively, and securable releasably in its depressed position by a latch member 222 urged by spring 224 to its engaged position, but being releasable, whereby to allow switches 182, 184, and 186 to return to normal, by the energization of an electromagnet 226. It will be understood that spring 224 acts on all of latches 222, that electromagnet 226 releases all of said latches, and that fingers 214 of each plunger are each operable to actuate switches 182, 184, and 186, although the showing of FIG. 6 is merely schematic. One

terminal of electromagnet 226 is connected to ground rail 4 by wire 212, and its opposite terminal is connected by wire 230 to wire 208 through a time delay device 232 which delays the energization of the electromagiet for a very short time after its circuit is otherwise completed.

It will be seen that the fingers 214 carried by each plunger 216 correspond in number, and in their relationship to switches 182, 184 and 186, to the number of buttons 92 carried by one of carriages A, B, C, D, E, and F, and to the relationship of said buttons 92 to switches 168, 170, and 172. Also, each plunger 216 carries one finger 214 operable to close switch 202, so that said switch is closed regardless of which pushbutton A, B, C, D, E, or F may be pushed. It will be seen that a carriage moving along holding loop X of the track will move continuously around and around said track until one of pushbuttons A, B, C, D, E, or F is pushed, since switch 164 will not be actuated. In fact, there may in normal operation be several carriages in the holding loop at the same time. When no pushbutton is depressed, all of switches 168, 170, 172, 182, 184, and 186 are normally closed to complete the circuit of solenoid 166, but the circuit is still interrupted by the open condition of switch 202. This prevents the almost continuous energization of said solenoid which would otherwise occur.

When the operator desires to divert a given carriage, say carriage E, from loop X into loop Y, he presses the corresponding pushbutton, in this case pushbutton E, and it is held by its corresponding latch 222, as shown. This closes switch 202, closes switches 182 and 186 on their normally open contacts 190 and leaves switch 184 closed on its normally closed contact 188. Then, when carriage E passes under bridge 174, its buttons 92 close switches 168 and 172 on their normally open contacts 180, and leaves switch closed on its normally closed contact 178. This completes a circuit from hot rail 6 through wire 204, switch 202 (now closed), wire 200, switch 168 and contact thereof (now closed), switch 182 and contact thereof (now closed), switch 170 and contact 178 thereof (now closed), switch 184 and contact 188 thereof (now closed), switch 172 and contact 180 thereof (now closed), switch 186 and contact 190 thereof (now closed), wires 206 and 208, solenoid coil 166 and wires 210 and 212 to ground rail 4. Coil 166 thus energized, actuates switch 164 to divert carriage E from track loop X to loop Y. Simultaneously with the completion of this solenoid circuit, the circuit of electromagnet 226 is completed from wire 206 through time delay device 232, wire 230, magnet 226, and wire 212 to ground rail 4. The magnet disengages the latch 222 of pushbutton E, allowing it to be elevated to normal by its spring 220, and allowing switches 182, 184, and 186 to return to normal to interrupt the solenoid circuit. However, time delay device 232 delays the actuation of magnet 226 for the short time, usually only a fraction of a second, necessary to allow the support rod 74 of carriage E to pass switch bar 130 of switch 164 and be diverted thereby into track Y. The delay must be sufficiently short that no immediately following carriage will also be diverted. Thus switch 164 will divert from track loop X to loop Y only the carriage for which the corresponding pushbutton A, B, C, D, E, or F has been pressed, and no other.

At the points of track convergence, namely point 96 at which delivery loop Y converges into holding loop X, and point 100 at which each station loop A, B, C, D, E, and F converge into delivery loop Y, the tracks converge at acute angles in the direction of carriage travel, so that no switch mechanisms are necessary. However, there remains the possibility that two carriages could approach the point of convergence simultaneously and collide, thereby causing damage, and the removal of the system from service for repairs. To prevent this occurrence, there is provided an arrangement best shown in FIGS. 79 Just before each point of tract convergence, on each track approaching said point, there is disposed a bridge member 234 similar to bridge members 162 and 174, each being disposed generally above the previously described stop section 106 of its associated track rail 6, and a bridge member 236 is disposed above the common track leaving the point of convergence, at a distance from said point in the direction of travel. For example, at point 96 as diagrammed in FIG. 9, bridges 234 are disposed above tracks X and Y ahead of point 96, and bridge 236 is disposed above track X after point 96. The bridge 234 above track X carries a single normally open switch 238, and the bridge 234 above track Y carries a single normally open switch 240, while bridge 236 carries a double-pole switch 242 having two normally closed poles 244 and 246. Each of switches 238, 240, and 242 is provided with an operating button 248 operable to be depressed to actuate said switches by a lever 250 pivoted to the switch housing and operated by the buttons 92 of the various carriages, in the manner of levers 160 of the switches 148, 150, 152, 168, 170, and 172. However, levers 250 differ from levers 160 in that levers 250 are sufficiently broad, transversely to the direction of travel, to be operated by any button 92 of any carriage, which of course means that switches 238, 240, and 242 are actuated by every carriage. The arrangement also includes a pair of relays, each of said relays having a normally closed pole 256 operable to be opened by energization of its coil 258, and a pole 260 normally closed on contact 262, but operable to close on contact 264 by the energization of coil 258. Stop section 106 of rail 6 of track X is connected to a continuously charged portion of said rail through wire 266, contact 262 and pole 260 of relay 254, and wire 268. Similarly, stop section 106 of rail 6 of track Y is connected to a continuously charged section of said rail through wire 270, contact 262 and pole 260 of relay 252, and wire 272. Thus, as long as the coil 258 of the relay 252 or 254 associated with each rail stop section is not energized, that stop section is charged and no stoppage of carriages will occur thereon.

If a carriage approaches convergence point 96 on either track X or track Y, for example track X, its buttons 92 close switch 238 momentarily. This completes a circuit from a con tinuously charged portion of hot rail 6 through wire 274, switch 238, wire 276, pole 256 of relay 254, wires 278 and 280, coil 258 of relay 252, and wire 282 to ground rail 4. Coil 258 of relay 252, thus energized, opens pole 256 of said relay, for a purpose to be described, disengages pole 260 thereof from contact 262, thereby interrupting the charging circuit of stop rail section 106 of track Y, and closes pole 260 on contact 264, establishing a holding circuit for coil 258 of relay 252 from pole 260 thereof through wire 284, pole 246 of switch 242, and wire 280 to said coil. Thus stop section 106 of track Y is not charged, so that any carriage moving thereon will stop to prevent any collision with the carriage on track X. Furthermore, stop section 106 of track Y will remain uncharged even after switch 238 reopens, by virtue of the holding circuit of coil 258 of relay 252, and will remain uncharged until the carriage on track X has passed through the track intersection and actuated switch 242 to open pole 246 thereof momentarily. This interrupts the holding circuit of coil 258 of relay 252, allowing said relay to return to normal, thus re-establishing the charging circuit of stop section 106 of track Y to allow any carriage stopped thereon to re-commence its travel. The fact that pole 244 of switch 242 is also opened momentarily has no effect, since relay 254 has not been actuated. If a carriage approaches intersection 96 on track Y, instead of track X as just described, relay 254 functions similarly to relay 252 to interrupt the charging circuit of stop section 106 of rail 6 of track X. Coil 258 of relay 252 has a circuit from a continuously charged section of rail 6 through wire 288, switch 240, wire 290, pole 256 of relay 252, wire 292, coil 258 of relay 254, and wire 294 to ground rail 4. A holding circuit for coil 258 of relay 254 extends from contact 264 of said relay through wire 296, pole 244 of switch 242, and wires 298 and 292 to said coil.

The use of normally closed poles 256 in relays 252 and 254 is necessary because of the fact that since each carriage must actuate its associated switch 238 or 240 before the right front contact wheel 54 of the carriage passes forwardly off of its associated stop rail section 106, there rises the possibility that a carriage approaching rail intersection 96, say on track X, and actuating relay 252 to interrupt the charge of stop section 106 of track Y, could itself be stopped by a carriage on track Y approaching and actuating switch 240 a split second later, before the carriage on track X had cleared its stop section 106. This would stop both carriages permanently, which of course cannot be permitted. However, the actuation of either relay 252 or 254 instantly opens pole 256 thereof, which interrupts the coil circuit of the other relay, so that said other relay cannot be actuated even a split second later, and the above described stoppage cannot occur.

In a normal usage of the system, a patron parks his automobile adjacent one of station loops A, B, C, D, E, or F, and will find one of trays 82 suspended conveniently adjacent his car by the corresponding carriage A, B, C, D, E, or F, for example carriage C in station loop C in FIG. 1, said carriage being at rest by virtue of its position on stop section 104 of rail 6 of that loop of the track. He then gives his order for food and beverages by use of the usual intercom system, not shown. The operator, usually inside of the restaurant building, then computes the charges, requests the patron to place money in payment thereof on tray 82, and instructs him to press pushbutton 122, which may be positioned on the intercom stand. This electrically charges rail stop section 104, causing the carriage to move forwardly until at least its front right contact wheel 54 engages a continuously charged section of rail 6, whereupon the carriage travels along its station loop, converging into delivery loop Y at the corresponding point 100, then around loop Y and into holding loop X at point 96, being protected against collision with any other carriage at any point or at point 96 by the previously described action of switches 238 and 240. The carriage will then travel continuously around holding loop X of the track, since switch 164 is not then actuated.

When the food and beverages are ready for delivery to a particular station, an operator depresses the corresponding pushbuttons A, B, C, D, E, or F. As previously described, this presets bridge switches 168, 170, and 172 of switch 164 to actuate said switch when the corresponding carriage, and no other, next passes beneath bridge 174, diverting said carriage into delivery loop Y, where it comes to rest on stop section 108 of the track. There an attendent places the order of food and beverages on tray 82, after first removing the payment money and making change if necessary, and presses pushbutton 126. This starts the carriage along delivery loop Y of the track, along which it travels until it reaches its assigned station loop, into which it is diverted by switch 128 of that loop. Due to the previously described selective action of bridge switches 148, 150, and 152 of switches 128, each carriage will enter only its assigned station loop. The carriage comes to rest on stop section 104 of its station loop, whereby the patron is served.

When the patron is ready to drive away, he again presses pushbutton 122 to return his carriage to the restaurant building, from which it is returned to its assigned station after the tray 82 is emptied and cleaned. For use in the event the patron should drive away without pressing pushbutton 122, a duplicate set of pushbuttons 122 could be provided within the restaurant building, each wired in parallel with one of switches 122 at the delivery stations.

While I have shown and described a specific embodiment of my invention, it will be readily apparent that many minor changes of structure and operation could be made without departing from the spirit of the invention.

What I claim as new and desire to protect by Letters Patent 1s:

1. A conveyor system comprising:

a. a conveyor track including a closed delivery loop and a series of station loops each diverging from said delivery loop at one point and re-converging therewith at another p b. a series of carriages powered to move along said track continuously in the same direction, each of said carriages being driven by an electric motor mounted thereon and which derives its electrical power from a pair of electrically charged rails forming elements of said track, with which said carriage has moving contact, each of said carriages corresponding to one of said station loops,

a series of normally open mechanical switches each operable when closed to divert carriages from said delivery loop into one of said station loops,

a switch operating means for each of said mechanical switches and operable to close said switch, said operating means including cooperating members carried respectively by said track just before the switch point and by each of said carriages, whereby to be brought into operative relationship by the movement of said carriages along said delivery loop of said track, said cooperating members being different for each carriage-switch combination whereby the mechanical switch for each station loop will be closed only by the carriage corresponding to that station loop, said cooperating members remaining in operative relationship only long enough to divert the associated carriage,

means for stopping each carriage automatically at a selected point of its corresponding station loop,

f. manually operable means for re-starting said carriage, and collision-preventing means including means operable by a first carriage as it approaches any point of track convergence between said station loops and said delivery loop, along either of said loops, to stop any second carriage approaching said point of track convergence along the other of said loops, and to re-start said second carriage only after said first carriage has passed through said convergence point, said collision-preventing means comprising means electrically insulating a section of at least one of said rails from the remainder of said rail, at points of both of said track loops at points of both of said track loops just before said point of track convergence, a concuctor connecting each of said insulated rail sections to the remainder of its associated rail, a normally closed first switch in each of said conductors, a pair of electric switch-operating devices each operable when energized to open one of said first switches, and to close a holding circuit for said switch-operating device to maintain said first switch open, a normally closed holding switch in each of said holding circuits, an operating circuit for each of said switch-operating devices, a normally open second switch in each of said switch-operating device circuits, said second switch being mounted adjacent said track at points just before said convergence point, respectively adjacent each of the approaching tracks, and operable to be mechanically engaged and closed by a carriage approaching on said track, the second switch closed by a carriage on either approaching track being operable to complete the circuit of the switch-operating device associated with the other approaching track, and means carried by the common track leaving said point of convergence, and operable to be engaged and actuated by any carriage leaving said point of convergence to open both of said holding switches.

a conveyor track including a closed delivery loop and a series of station loops each diverging from said delivery loop at one point and re-converging therewith at another point, a portion of said delivery loop remote from said station loops being closed to present a continuous holding loop of track, the remainder of said delivery loop diverging from and converging with said holding loop,

a series of carriages powered to move along said track continuously in the same direction, each of said carriages corresponding to one of said station loops a se es of normally open mechanical switches each operable when closed to divert carriages from said delivery loop into one of said station loops,

a switch operating means for each of said mechanical switches and operable to close said switch, said operating means including cooperating members carried respectively by said track just before the switch point and by each of said carriages, whereby to be brought into operative relationship by the movement of said carriages along the delivery loop of said track, said cooperating members being different for each carriage-switch combination whereby the mechanical switch for each station loop will be closed only by the carriage corresponding to that station loop, said cooperating members remaining in operative relationship only long enough to divert the associated carriage,

means for stopping each carriage automatically at a selected point of its corresponding station loop,

f. manually operable means for re-starting said carriage,

a normally open mechanical master switch operable when closed to divert carriages from said holding loop to said delivery loop,

h. operating means for said mechanical master switch including the members carried by said carriages and cooperating with the members carried by the track at each of the station loop switches to close said station loop switches, hereinafter called the carriage members and which are differently arranged on each carriage; and cooperating members carried by said track holding loop just before the master switch point, hereinafter called the track members, and

. manually adjustable means whereby said track members may be set selectively to cooperate operatively with the carriage members of any one carriage. 

1. A conveyor system comprising: a. a conveyor track including a closed delivery loop and a series of station loops each diverging from said delivery loop at one point and re-converging therewith at another point, b. a series of carriages powered to move along said track continuously in the same direction, each of said carriages being driven by an electric motor mounted thereon and which derives its electrical power from a pair of electrically chargEd rails forming elements of said track, with which said carriage has moving contact, each of said carriages corresponding to one of said station loops, c. a series of normally open mechanical switches each operable when closed to divert carriages from said delivery loop into one of said station loops, d. a switch operating means for each of said mechanical switches and operable to close said switch, said operating means including cooperating members carried respectively by said track just before the switch point and by each of said carriages, whereby to be brought into operative relationship by the movement of said carriages along said delivery loop of said track, said cooperating members being different for each carriage-switch combination whereby the mechanical switch for each station loop will be closed only by the carriage corresponding to that station loop, said cooperating members remaining in operative relationship only long enough to divert the associated carriage, e. means for stopping each carriage automatically at a selected point of its corresponding station loop, f. manually operable means for re-starting said carriage, and g. collision-preventing means including means operable by a first carriage as it approaches any point of track convergence between said station loops and said delivery loop, along either of said loops, to stop any second carriage approaching said point of track convergence along the other of said loops, and to re-start said second carriage only after said first carriage has passed through said convergence point, said collisionpreventing means comprising means electrically insulating a section of at least one of said rails from the remainder of said rail, at points of both of said track loops at points of both of said track loops just before said point of track convergence, a concuctor connecting each of said insulated rail sections to the remainder of its associated rail, a normally closed first switch in each of said conductors, a pair of electric switch-operating devices each operable when energized to open one of said first switches, and to close a holding circuit for said switch-operating device to maintain said first switch open, a normally closed holding switch in each of said holding circuits, an operating circuit for each of said switchoperating devices, a normally open second switch in each of said switch-operating device circuits, said second switch being mounted adjacent said track at points just before said convergence point, respectively adjacent each of the approaching tracks, and operable to be mechanically engaged and closed by a carriage approaching on said track, the second switch closed by a carriage on either approaching track being operable to complete the circuit of the switch-operating device associated with the other approaching track, and means carried by the common track leaving said point of convergence, and operable to be engaged and actuated by any carriage leaving said point of convergence to open both of said holding switches.
 2. A system as recited in claim 1 with the addition of a normally closed third switch disposed in the operating circuit of each of said switch operating devices, and operable to be opened by the energization of the other of said switch-operating devices.
 3. A conveyor system comprising: a. a conveyor track including a closed delivery loop and a series of station loops each diverging from said delivery loop at one point and re-converging therewith at another point, a portion of said delivery loop remote from said station loops being closed to present a continuous holding loop of track, the remainder of said delivery loop diverging from and converging with said holding loop, b. a series of carriages powered to move along said track continuously in the same direction, each of said carriages corresponding to one of said station loops, c. a series of normally open mechanical switches each operable when closed to divert carriages from said Delivery loop into one of said station loops, d. a switch operating means for each of said mechanical switches and operable to close said switch, said operating means including cooperating members carried respectively by said track just before the switch point and by each of said carriages, whereby to be brought into operative relationship by the movement of said carriages along the delivery loop of said track, said cooperating members being different for each carriage-switch combination whereby the mechanical switch for each station loop will be closed only by the carriage corresponding to that station loop, said cooperating members remaining in operative relationship only long enough to divert the associated carriage, e. means for stopping each carriage automatically at a selected point of its corresponding station loop, f. manually operable means for re-starting said carriage, g. a normally open mechanical master switch operable when closed to divert carriages from said holding loop to said delivery loop, h. operating means for said mechanical master switch including the members carried by said carriages and cooperating with the members carried by the track at each of the station loop switches to close said station loop switches, hereinafter called the ''''carriage members'''' and which are differently arranged on each carriage; and cooperating members carried by said track holding loop just before the master switch point, hereinafter called the ''''track members,'''' and i. manually adjustable means whereby said ''''track members'''' may be set selectively to cooperate operatively with the ''''carriage members'''' of any one carriage. 